Clutch.



J. B. ENTZ.

CLUTCH. APPLIoATIoN FILED AUG. 11, 1905.

Patented Oct. 14, 1913.

MX/fesses.

. UNTTED STATES PATENT FPTQE.

JUSTUS B, ENTZ, OF PHILADELPHIA, PENNSYLVANIA,

ULUTCH.

To all @v7/.0m It may concern: v

Be it known that I, JUs'rUs B. ENTZ, a

. citizen of the United States, residing Vat Philadelphia, in the countyof Philadelphia and State of Pennsylvania, have invented certain new anduseful Improvements in Clutches; and I do hereby declare the followingto be a full, clear, and exact description of the-invention, suchaswillenable others skilled in the art to which it appertains to make and usethe same.

My invention relates to new and useful improvements in clutches employedto conneet a driving memberto a driven member, and applies to variousforms of the type known as friction clutches, and is not alone suitablefor the lform illustrated, which is that' generally known as theconeclutch, and moie particularly relates to the control of the pressureexisting between the friction surfaces.

In clutch mechanisms of the class described, it is customary to applythe pressure between the .friction surfaces by means of direct action ofa spring on one' of the surfaces, and the action of this spring istcmporarily counteracted during the disengagement of the clutch membersby a lever or a system of levers. ln this arrangement as ordinarilyconstructed, when it is desired to 'bring clutch members into engagementthe pressure on the hand lever or foot lever is released as gradually aspossible and the movable member of the clutch is brought into engagementwith the non-niovable member, and the full pressure of the spring isthen exerted. t is easily seen that there is,

a point in the movement of the lever or system vof levers on one side ofwhich the tension of the spring is entirely absorbed by the levers, andon the other side of which itis entirely absorbed by the pressurebetween the friction surfaces; that'is, it is impossible the pressurebetween the friction 'surfaces is Specification of Letters Patent.

Patented (Pct, Ml, 1913.

Application led August 11, 1995. Serial No. 273,745.

very gradual, ranging from Zero to the full power of the spring, and sopermit a gradual acceleration of speed of the driven mem-l ber until themaximum or speed of the driving member is reached'.

The invention consists in the improved construction of the variouselements and their arrangement in operative combination to be fullydescribed hereinafter, the novelty of which will be particularly pointedout and distinctly claimed.

The accoii'ipanying drawing represents a view in elevation, partsection, of the a )plication of my invention to a motor ve icle clutchmechanism.

A and B are the driving and driven members respectively of the clutch, Abeing longitudinally immovable, while B is movable along the shaft C sothat it may be brought into or out of contact with A as desired by meansvof the mechanism hereinafter. described. Power is supplied to A fromthe inotor l, 2. 'Ihe shaft C is rigidly attached to the member A androtates with it at all times, while the hollow shaftD is' rigidlyattached to the member B and rotates wit it. vThe member' B is normallyheld in contact with A by means of the spring E acting against thecollar F on the shaft C and the shoulder (ir on the hollow shaft D. Aand B are separated by incans of the lever H pivoted at R, actingthrough the arm I and. the link J upon the floating lever K, which isconnected to t-he movable shaft D in any of the wellkiiown methods ofconstruction, such as lthe loose ring L pivoted at T, and *the shoulderL of the shaft D. y

N is a rigid member immovable with respect to the other parts of themechanism, against which one end of the spring O abuts, the other endbeing held by the collar P adjustable by means of threaded members U i i.lars as shown, to .bring about any desired relation between the twosprings.

Tt will be noted that the movement of the member B, or (if the point leilongitudinal T, (which is yapproximately` the point of' connection ofthe lever lfwith the shaft il) along the shaft C, between thepositionsof no contact between A and B and full contact, thatis, where the wholepressure of the s rin E is a lied is ver small and in constructionspreviously* used with a rigid'system of levers it has been impossible tograduate the application of the'pressure of the spring lil when theclutch was to be put in action; that is, when the surfaces A and B comefirst into contact there is no pressure exerted between the frictionsurfaces, and the next small movement of the llever K releases thepressure between thev collar L and the shoulder' L and immedi-- atelywithout any gradation the full4 pressure of the spring E is applied tothe friction surfaces and the driven member B must change suddenly. fromits initial ve- Vvelocity of the driving member A. The

manner in which this gradual application of pressure is obtained will beclearly understood by reference to the drawings as followsz-Referring tothe figure the parts are shown in the relation of nearly full engagementof the clutch members A and B-in full engagelnent there would be aslight clearance between L and L-the spring E is exerting nearly itsfull force while the spring O is out of action owing to the shoulder Vacting as a stop against the y rigid member N. To release the clutchmembers power is applied' to the lever H which acting through the arm land the link J applies 'the power to the lever K at the point W. J ustat this instant lever K is fulcrumed at the point T so there is no powerapplied to overcome the force of the spring E, but as the power appliedto H is increased the movement of the rod M through its connection at Sto the lever K gradually compresses the spring Q to such a point that Sbecomes the fulcrum of the lever K although not necessarily a fixedfulcrum, and at this instant the point T begins to move and the spring Eis correspondingly compressed at the same time that the members A and Baredisengaged. But it' will be seen that through this move- :ment thepower of the spring E is not suddenly overcome as the fulcrum S willcontinue to move for some time after the beginning of the compression ofspring E according to the relative adjustments of the two springs E andand during this movement of the point S the act of compressing thespring O is lworking against the compression of the spring E andtherefore relieving l nor/mia the ressure between the friction surfacesA of A and B very gradually. ln the application of the clutch thereverse movements take place as follows r-"p-on a slight diminution ofthe power applied to H the spring E expands until the friction surfacesA and E are just in contact, the 'pointS- in the meantime moving slowlytothe right. At this instant the spring E is tending ,to force thefriction surfaces into engagement'which would mean a movement of thepoint T to the left, while the spring i) acting through the rod M andits connection S is tending to move the point T to the right, the pointS being in this case the movable fulcrum so that it is seen that thespring O is counteracting the effect of the spring E and thiscounteraction continues with the gradual release of pressureon lthelever H until the shoulder V comes into contact with the fixed rigidmember -N and acts as a stop' gradually reduce the pressure tending to,

keep the friction member B out of engab ment. In this manner the,surface of B at the moment of contact with the friction sur-- face of Ais in that position floating and the pressure between the surfacesincreases from Zero to the maximum, which is predetermined by theadjustment of spring E, the increase Ivarying as the tension is relievedon the spring O by an appreciable movement of the operating lever Hoperated by thepedal.

It will be seen that by properly proportioning the springs O and E andby means of the adjustments afforded by the threaded members it will bepossible to secure any desired relation between these springs and soabsolutely control the gradationA of the application of pressure betweenthe friction v Surfaces of A and 1' B, and it is in this gradualapplication of pressure between the j friction surfaces and the controlof the same that my invention lies.

l/Vhile l have illustrated a specific arrangement of parts and themethod of carrying ont "my invention, ity is of course understood thatthe application of the improvement would not be limited to the preciseform shown and described but is applicable generally to that class ofclutches tending to move said fulerum against the pressure of said firstmentioned spring, a

pedal and connections adapted to operate the outer end of said lever,substantially as shown and described.

2. In a friction clutch, the friction surfaces one being movable intoand out of engagement with the other, a lever to move .end of said leverand tending one of said. surfaces ont of engagement, a pedal and linl`rconnection to the end of said lever, a floating spring pressed:t'ulcruin intermediate the ends of said lever, and a spring opposingthe motion of the opposite to force the movable clutch member to bringthe fri@ 2o tional surfaces into engagement.

JUSTUS B,

ln the presence ofm l. Kirwan, RUDOLPH RUGE.

ENTE.

